Задача id13788

Electrons with energy Wк = 100 eV fall at an angle j = 30° to the normal onto a system consisting of two parallel grids, between which a potential difference U1 = 36 V is created (figure). Find the relative refractive index of the media located on both sides of the grid. At what potential difference U2 will the electrons be completely reflected from the second grid?

Detailed solution. Format gif